Kai, That's correct. A network purchasing transit will advertise its internally-originated prefixes, as well as those it's learning from downstream customers, to its provider. (At least that's the theory. It's not terribly uncommon for transit purchasers to advertise a full table, or for their providers to have lax or non-existent filters, but that's neither here nor there. :) I'm not sure what "valley-free" means in this context. You might want to try the Rosetta Stone patches and make sure your copy is up to date. Drive Slow, Paul Wall http://www.linkedin.com/in/paulwall On Tue, Sep 2, 2008 at 7:45 PM, Kai Chen <kch670@eecs.northwestern.edu> wrote:
Just want to ask a direct question. Will an AS export all it gets from its customers and itself to its providers? Or even under valley-free, the BGP export policy is also selective?
Thanks a lot, -- -Kai